Connections for hoses and tubes of the most varied type are known in the prior art. Many of these connections utilize clamps which can be tightened in a number of ways. For example, they may be tightened by a plastically deformable, so-called "Oetiker" ear as disclosed in U.S. Pat. Nos. 2,614,304; 2,847,742; 3,082,498 and 4,299,012. Other types of clamps utilize a screw-type tightening mechanism or toggle-type tightening mechanism as disclosed, for example, in U.S. Pat. Nos. 3,475,793 and 4,521,950. Other clamps rely on the threaded engagement between a nipple member and a sleeve surrounding the same, as disclosed, for example, in U.S. Pat. Nos. 2,399,790; 2,865,094 or 3,870,349. However, the prior art clamps are not particularly suitable for flexible, stretchable hoses or tubes, such as silicon tubes which have very smooth, external surfaces and are highly stretchable. Added thereto is the problem of the small size of such tubes as are used for intravenous feeding, particularly in connection with drip chambers. Attempts to fasten such hoses onto nipple structures by means of clamps have not proved successful to date. Coupling devices with clamping surfaces are also known in the prior art, as exemplified by U.S. Pat. Nos. 4,208,067; 4,790,569 and 4,923,226. However, they usually involve double-frusto conical surfaces which require a radial fastening band or the like to hold together and tighten up arcuate sections. Quick disconnect pipe couplings with interlocking action by bayonet-type arrangements involving relative rotation are also known in the prior art, as disclosed, for example, in U.S. Pat. Nos. 699,366 and 3,583,667. However, these devices are, for the most part, complicated in structure and unsuitable as coupling devices for small diameter tubes with great stretchability and flexibility and with slippery outer surfaces. Furthermore, they do not satisfy the requirement for ease of connection and disconnection as required in hospital environments.